Text book pages: 143 - 149
Websites: www.themathlab.com/dictionary/twords/twords.htm (scroll down to transversal)
www.themathlab.com/dictionary/pwords/pwords.htm (scroll down to parallel)
Visit the textbook for more help and practice problems

This section will teach you how to find the measurements of other angles while only knowing the measurement of one of the angles. There are four theorems and one postulate that will help prove the measurements:

Theorems:
Alternate Interior Angles:
If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruentexternal image mcd_ma_geo_lsn_0395937779_p143_f03a.gif
Consecutive Interior Angles:
If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementaryexternal image mcd_ma_geo_lsn_0395937779_p143_f03b.gif
Alternate Exterior Angles:
If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruentexternal image mcd_ma_geo_lsn_0395937779_p143_f03c.gif
Perpendicular Transversal:
If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the otherexternal image mcd_ma_geo_lsn_0395937779_p143_f03d.gif

Postulate:
Corresponding Angles:
If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent external image mcd_ma_geo_lsn_0395937779_p143_f02a.gif
Vocabulary:
Transversal- a line intersecting a two or more lines
Parallel lines- side by side and having the same distance continuously in between them

Sample Problems:

1)
3-3_#4.jpg

2) Find m<1

Consecutive Interior Angles
3-3_#9.png

3)
3-3_#5.png


On your own:

1) Find x. State which theorem you used.

3-3_5.png


2) Find y. State which theorem you used.

3-3_6.png


3) Name the theorem / postulate you used to find each
3-3_7.png


4) Complete the proof.
3-3_4.png